This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. NMR Spectroscopy The sample (70 mg) was deuterium-exchanged by lyophilization from D2O, dissolved in 700 uL D2O (99.996 % D). Heteronuclear single quantum coherence (gHSQC) spectra were acquired on a Varian Inova-500 MHz spectrometer at 313 K (40 [unreadable]C). Proton chemical shifts were measured relative to DSS (delta=0.00 ppm). The spectra were recorded with a spectral width in the proton dimension of 2382 Hz and in the carbon dimension of 8750 Hz. The acquisition time was 0.20 s, and 100 increments were collected with 32 scans each. The one-bond C-H coupling constant was set at 140 Hz.